This invention deals with novel sulfated copolymers of hydroxyethyl methacrylate and alkyl esters of acrylic acid and sulfated copolymers of hydroxyethyl acrylate and alkyl esters of methacrylic acid. The copolymers are useful as components in aqueous hair shampoo systems to provide an after-shampoo conditioning effect.
The primary function of any hair shampoo product is, of course, to thoroughly remove from the hair accumulated deposits of sebum, airborne particulate materials, and residues of hair treating compositions such as hair sprays or other grooming aids. At least as important, however, from the standpoint of consumer satisfaction are the wet and dry combing properties of the hair after shampooing and the feel and appearance of the hair. As a general rule, shampoos that thoroughly clean the hair tend to leave it hard to comb and in a dry, fly-away condition. Conversely, shampoos which avoid "overdrying" the hair usually do so at the expense of cleaning effectiveness.
We have discovered a class of materials which when formulated in conventional, aqueous shampoo systems, provide unexpected post-shampoo conditioning benefits. Not only is a smooth, soft feel imparted to the hair, but combing, both wet and dry, is markedly improved. Furthermore, the hair appears to have more body, being more manageable, and exhibits improved luster. These benefits are derived from the inclusion of certain sulfated copolymers of hydroxyethyl methacrylate and alkyl esters of acrylic acid and sulfated copolymers of hydroxyethyl acrylate and alkyl esters of methacrylic acid as will be hereinafter more fully described.
The prior art describes anionic shampoos containing a variety of polymeric ingredients, for example U.S. Pat. No. 3,969,500 dealing with hair shampoos containing water soluble carboxylic linear polymers such as polymethacrylic acid. The art also described hair treating compositions such as hair sprays and setting agents based upon a variety of acrylic and sulfonated polymers, for example U.S. Pat. Nos. 3,577,518 and 3,972,336 dealing with hair setting preparations based upon acrylic or methacrylic esters and sulfonated polystyrene respectively. Nowhere, however, does the art teach that sulfated copolymers of hydroxyethyl methacrylate and alkyl esters of acrylic acid and sulfated copolymers of hydroxyethyl acrylate and alkyl esters of methacrylic acid may be useful as surfactant conditioning ingredients in aqueous hair shampoo compositions.